That infact is not how insurance works. You don't charge low risk people insane premia because it isn't fair. My car insurance is far cheaper than my sister's for this reason for example.
Even if I had an event (outside something way out in the tails where I might not even want the treatment anyway if it's free because my QoL suffers too much either way) I'm coming out with a loss because I'm forced to subsidize care for high risk people as well as very bloated administration. Having the insurance doesn't make sense.
even when you're one of the people that needs healthcare
Insurance is an instrument for trading volatility not socializing costs. Those are radically different things.